What is dot pitch? | HowStuffWorks What is dot pitch? NEXT PAGENEXT The dot pitch rating of a monitor tells you just how sharp the displayed image will be. Dot pitch is measured in millimeters (mm), and a smaller number means a sharper image. How you measure the dot pitch depends on the technology used. In most CRTs you measure dot pitch as the distance between holes in the shadow mask. The shadow mask is a metal screen filled with holes through which the three electron beams pass that focus to a single point on the tube's phosphor surface. Monitors based on the Trinitron technology, developed by Sony , use an aperture grill instead of a shadow mask. The aperture grill consists of tiny vertical wires. The dot pitch of one of these monitors is measured by the horizontal distance between wires. In LCDs and the majority of other display technologies, dot pitch refers to the distance between subpixels of the same color in pixel triads. In computer displays, common dot pitches are .31mm, .28mm, .27mm, .26mm, and .25mm.

Traditional televisions often use a larger dot pitch, about .51 mm, and large screen TVs or projection devices can go up to 1 millimeter in pitch. Up Next How Elumens Vision Station Works The smaller and closer the dots are to one another, the more realistic and detailed the picture appears. When the dots are farther apart, they become noticeable and make the image look grainier. You will usually want a .28mm or finer. Anything larger than that on a typical monitor will begin to appear grainy. The dot pitch translates directly to the resolution on the screen. If you were to put a ruler up to the glass and measure an inch, you would see a certain number of dots, depending on the dot pitch. See below for the number of dots per square centimeter and per square inch in each of these dot pitches: Dot Pitch .25mm What is display? - Definition from WhatIs.com The size of the screen The projection technology Color Capability Today, most desktop displays provide color. Notebook and smaller computers sometimes have a less expensive monochrome display. Displays can usually operate in one of several display modes that determine how many bits are used to describe color and how many colors can be displayed.

A display that can operate in SuperVGA mode can display up to 16,777,216 colors because it can process a 24-bit long description of a pixel . The number of bits used to describe a pixel is known as its bit-depth . The 24-bit bit-depth is also known as true color . It allows eight bits for each of the three additive primary colors - red, green, and blue. Although human beings can't really distinguish that many colors, the 24-bit system is convenient for graphic designers since it allocates one byte for each color. The Visual Graphics Array ( VGA ) mode is the lowest common denominator of display modes. Depending on the resolution setting, it can provide up to 256 colors. Sharpness and Viewability The absolute physical limitation on the potential image sharpness of a screen image is the dot pitch , which is the size of an individual beam that gets through to light up a point of phosphor on the screen. (The shape of this beam can be round or a vertical, slot-shaped rectangle depending on the display technology.) Displays typically come with a dot pitch of .28 mm (millimeters) or smaller.

The smaller the dot pitch in millimeters, the greater the potential image sharpness. The actual sharpness of any particular overall display image is measured in dots-per-inch ( dots per inch ). The dots-per-inch is determined by a combination of the screen resolution (how many pixel s are projected on the screen horizontally and vertically) and the physical screen size. The same resolution spread out over a larger screen offers reduced sharpness. On the other hand, a high-resolution setting on a smaller surface will product a sharper image, but text readability will become more difficult. Viewability includes the ability to see the screen image well from different angles. Displays with cathode ray tubes ( CRT ) generally provide good viewability from angles other than straight on. Flat-panel displays, including those using light-emitting diode and liquid crystal display technology, are often harder to see at angles other than straight on. The Size of the Screen On desktop computers, the display screen width relative to height, known as the aspect ratio , is generally standardized at 4 to 3 (usually indicated as "4:3"). Screen sizes are measured in either millimeters or inches diagonally from one corner to the opposite corner.

Popular desktop screen sizes are 12-, 13-, 15-, and 17-inch. Notebook screen sizes are somewhat smaller. The Projection Technology Most displays in current use employ cathode ray tube ( CRT ) technology similar to that used in most television sets. The CRT technology requires a certain distance from the beam projection device to the screen in order to function. Using other technologies, displays can be much thinner and are known as flat-panel displays . Flat panel display technologies include light-emitting diode (LED), liquid crystal display ( LCD ), and gas plasma. LED and gas plasma work by lighting up display screen positions based on the voltages at different grid intersections. LCDs work by blocking light rather than creating it. LCDs require far less energy than LED and gas plasma technologies and are currently the primary technology for notebook and other mobile computers. Displays generally handle data input as character maps or bitmap s. In character-mapping mode, a display has a preallocated amount of pixel space for each character. In bitmap mode, it receives an exact representation of the screen image that is to be projected in the form of a sequence of bits that describe the color values for specific x and y coordinates starting from a given location on the screen.

Displays that handle bitmaps are also known as all-points addressable displays. This was last updated in April 2005 Related Terms All About Monitors: CRT Vs. LCD - Webopedia.com All About Monitors: CRT vs. LCD computer When shopping for a new computer system, we tend to fret over such things as the CPU speed or hard disk size, but what about the one component of your system that is used just as much? Of course we're talking about the monitor . Often referred to as a display screen , a video display terminal (VDT) or visual display unit (VDU), the monitor is the component of your computer system that displays the messages and data being processed and utilized by the computer's CPU. The two types of monitor technologies available to consumers are available in CRT monitors and LCD monitors. There are big differences between LCD and CRT, and while LCD technology has advanced to the point where its viewing quality is comparable to CRTs, many people today still choose to purchase a CRT monitor. CRTs are bigger and bulkier than an LCD, they consume more power and are prone to screen flicker .

LCD monitors, however, are more expensive when compared to CRTs, they introduce the problem of viewing angles, and generally have less accurate color replication. Each type of monitor, as you can see, has its advantages and disadvantage. In this article we will provide a comparison of CRT and LCD monitors, along with defining some of the many specifications and terminology you should be aware as you decide between an LCD and CRT monitor. CRT Monitors Sort for cathode-ray tubes, CRT monitors were the only choice consumers had for monitor technology for many years. Cathode ray tube (CRT) technology has been in use for more than 100 years, and is found in most televisions and computer monitors. A CRT works by moving an electron beam back and forth across the back of the screen. Each time the beam makes a pass across the screen, it lights up phosphor dots on the inside of the glass tube, thereby illuminating the active portions of the screen. By drawing many such lines from the top to the bottom of the screen, it creates an entire screen of images. LCD/Flat panel Monitors Short for liquid crystal display, LCD technology can be found in digital watches and computer monitors.

LCD displays use two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light. Color LCD displays use two basic techniques for producing color: Passive matrix is the less expensive of the two technologies. The other technology, called thin film transistor ( TFT ) or active-matrix , produces color images that are as sharp as traditional CRT displays, but the technology is expensive. CRT vs. LCD - The Pros and Cons of Each Resolution & Viewing Quality Resolution on a CRT is flexible and a newer model will provide you with viewing resolutions of up to 1600 by 1200 and higher, whereas on an LCD the resolution is fixed within each monitor (called a native resolution). The resolution on an LCD can be changed, but if you're running it at a resolution other than its native resolution you will notice a drop in performance or quality. Both types of monitors (newer models) provide bright and vibrant color display. However, LCDs cannot display the maximum color range that a CRT can.

In terms of image sharpness, when an LCD is running at its native resolution the picture quality is perfectly sharp. On a CRT the sharpness of the picture can be blemished by soft edges or a flawed focus. A CRT monitor can be viewed from almost any angle, but with an LCD this is often a problem. When you use an LCD, your view changes as you move different angles and distances away from the monitor. At some odd angles, you may notice the picture fade, and possibly look as if it will disappear from view. Refresh Rate Some users of a CRT may notice a bit of an annoying flicker, which is an inherent trait based on a CRTs physical components. Today's graphics cards, however, can provide a high refresh rate signal to the CRT to get rid of this otherwise annoying problem. LCDs are flicker-free and as such the refresh rate isn't an important issue with LCDs. Dot Pitch Dot pitch refers to the space between the pixels that make up the images on your screen, and is measured in millimeters. The less space between pixels, the better the image quality.

On either type of monitor, smaller dot pitch is better and you're going to want to look at something in the 0.26 mm dot pitch or smaller range. Screen (viewable) Size Most people today tend to look at a 17-inch CRT or bigger monitor. When you purchase a 17-inch CRT monitor, you usually get 16.1 inches or a bit more of actual viewing area, depending on the brand and manufacturer of a specific CRT. The difference between the "monitor size" and the "view area" is due to the large bulky frame of a CRT. If you purchase a 17" LCD monitor, you actually get a full 17" viewable area, or very close to a 17". Physical Size There is no denying that an LCD wins in terms of its physical size and the space it needs. CRT monitors are big, bulky and heavy. They are not a good choice if you're working with limited desk space, or need to move the monitor around (for some odd reason) between computers. An LCD on the other hand is small, compact and lightweight. LCDs are thin, take up far less space and are easy to move around.

An average 17-inch CRT monitor could be upwards of 40 pounds, while a 17&-inch LCD would weigh in at around 15 pounds. Price As an individual one-time purchase an LCD monitor is going to be more expensive. Throughout a lifetime, however, LCDs are cheaper as they are known to have a longer lifespan and also a lower power consumption. The cost of both technologies have come down over the past few years, and LCDs are reaching a point where smaller monitors are within many consumers' price range. You will pay more for a 17" LCD compared to a 17" CRT, but since the CRT's actual viewing size is smaller, it does bring the question of price back into proportion. Today, fewer CRT monitors are manufactured as the price on LCDs lowers and they become mainstream. DID YOU KNOW... In March 2009 Hitachi Displays plead guilty to LCD price fixing joining LG Display, Chunghwa Picture Tubes (CPT) and Sharp. Hitachi will pay US$31 million in fines for its role in fixing LCD prices sold to Dell for LCD monitor and notebook PC applications according to the US Department of Justice.

[Source: Display Blog] Based in Nova Scotia, Vangie Beal is has been writing about technology for more than a decade. She is a frequent contributor to EcommerceGuide and managing editor at Webopedia. You can tweet her online @AuroraGG. How computers make images Pictures on Computers: Digital Image is often used to describe a computer generated image. Digital is referring to the two digits of the binary number system...0 and 1. Each binary number is called a "bit". All the information and commands used within a computer are expressed in this binary number system. Computers may offer higher forms of notation such as our alphabet and the decimal numbers, but they are first stored as combinations of 0s and 1s. A group of eight bits is called a "byte". It might look like this: 01100111. If you add up all the possible combinations of eight 0s and 1s you will arrive at the number 256. This is 2 to the eighth power. Think about it...a binary number system (base 2 in math talk)...a byte containing 8 bits... 256, or 2 to the eighth power, of possible combinations.

Coincidence???? Bytes are handy for defining 256 levels of color in images but they are also the computer "words" used to describe the letters, numbers and characters of the alphabet. Raster Image is often used to describe images made of pixels. A digital image is a collection of data, displayed on a display grid. This grid is called a raster. The raster image is a collection of data. Each pixel is defined by numbers expressed in bits. A 1-bit number can describe two colors for each pixel. If we assign more bits to each pixel, we can get more colors out of every pixel. Every bit doubles the number of colors: 1-bit describes 2 colors, 2-bit describes 4 colors, 3-bit describes 8 colors, 4-bit describes 16 colors...and so on. Our computers usually work with of 8-bits of data. This gives 256 colors, or levels of gray tones. The RGB or CMYK channels in Photoshop are not necessarily a "color"; they are data, which displays in a channel as a gray image and will be translated to color only when interpreted by an output device - monitors, printers or printing processes.

Photoshop channels in additon to the image channels are used as masking or selection tools.The pixels in a mask channel can be instructed to apply an effect on image pixels at the same raster location. Computer pictures are really information, describing tones or colors. This is stored in a file similar to a spread sheet. Let's look at a computer picture. This picture is really a grid with 400 squares across and 257 down. Now take a look at an extreme close-up of the red logo on the can of beans... Look, it's really row after row of little squares. These squares are the most basic building blocks of any computer graphic; they are called PICTURE ELEMENTS... PIXELS, for short. Each and every one of this photo's pixels is recorded in the computer file. The file has the location, or address, of each pixel on the grid (440 x 257 squares) and the description of the color of each pixel. Bitmapped image is a term that comes from this "map" of pixels. Below is a small portion of the map of a 24-bit image. This is a huge amount of information and that is why graphics files are so large. How do we define a color?

For any graphics displayed on a color computer monitor we have swiped a trick for the good old human eyeball. Did you know... We can only see 3 colors! This sounds absurd...but here is how it works. Inside our eyes the images we see pass through the lens and focus onto the retina. The retina is covered with special cells which are sensitive to light. These cells come in three types: Red sensitive, Blue sensitive and Green sensitive. Everything we see is gathered as a collection (like a grid!...again we have a grid) of red, green and blue information. This information is sent back to our wonderful brain where it is interpreted. By analyzing the strength of the red, green and blue signals from the eyes, the brain creates our perception of images and all the colors of the rainbow. This happens continuously and in great detail (resolution)...our brain is one SUPER computer! Welcome to the RGB Color Space. There are more than one way to describe color. Red, green and blue (RGB) is one. CMY, cyan, magenta and yellow is another color space. This is the basis for the inks used to print color in magazines.

Because the inks can't do a perfect job of making colors, printers also use black ink (referred to as K) and the printer's color space is called CMYK. How does the Monitor do it? Remember those pixels in the image above? They are a pattern of multicolored squares. Can the monitor display those pixels? Here is the old eyeball trick! The monitor is built to display three colors...Red, Green and Blue. Mixed together, they can more or less create the same range of colors that our eyes and brain can see. The monitor uses an electron gun to shoot a stream of electrons (electricity) onto a chemical called a phosphor. When electrons strike a phosphor, the phosphor glows, sending off light. The phosphors come in three types; one emits Red light, one emits Green and one emits Blue. They are like tiny colored light bulbs, each on its own dimmer switch. Now it gets tricky. To create a full screen image the electron gun is swept across the screen horizontally, row by row from top to bottom. It must do this cycle very quickly and repeat itself to keep those phosphors lit up. This cycling speed is what is called the refresh rate.

This is usually around 75 times a second, or 75Hz. The phosphors are arranged in a pattern and a very thin metal mask is used to define the pattern precisely. Below is a close-up a a monitor (this is a very old non-multiscan model, so the pattern is very simple)... Do you see the pattern and the color gradation? The light and dark tones are created by varying the amount of electricity the electron gun shoots at each pixel. The more electrons the brighter the color. The brightest area around the lettering is what you would see as white when you look at the screen. Because they are too small for our eyes to separate, the red, green and blue lights are seen as white when they reach our brains. Red, green and blue are called the "Additive Primary Colors" because they form white light when added together. Here is an even closer view. Each of those triangular clusters of a red, green and blue dot is the method your monitor uses to portray each of those pixels we saw above in the can of green beans photo. A square pixel is displayed by a 3-color cluster of phosphor dots on the monitor. So, let's get this straight!

Suppose your monitor is set to display 800 pixels wide and 600 pixels tall. The electron gun knows how many electrons to shoot at every red, green and blue dot on the screen. The beam of electrons zips across the rows of dots, lighting up the phosphors. It goes line-by-line, top to bottom shooting 800 red, 800 green and 800 blues dots on every line. It does each of the 600 rows to cover the screen. The phosphors only glow for an instant, so the electron gun shoots the entire screen 75 times every second to keep the image bright. By the way, the electron gun is a stream of electrons which pass by a set of electromagnets which deflect the stream. The variance in the magnets is what moves the beam from side to side and up and down. This all happens in a vacuum inside the picture tube of your monitor. Those new flat panel displays... The new flat panel monitors are much more direct. They are a grid of tiny solid state light emitting thingies...like tiny light bulbs on a reader board sign, and they simply light up. No electron guns, etc. Now that we have the monitor working...

We have a computer file which defines a grid of pixels. Each pixel has a color value. The monitor converts each pixel's color value into a red, green and blue intensity which it shoots at the 3-dot cluster representing the pixel. What kind of information defines a pixel? Computers didn't always have the power to make color. The early models had only two options...a pixel was on or it was off. This was 1-bit information. Early color monitors only had limited numbers of colors. Early computers only "knew" how to make 16 colors so a pixel required the information to provide 16 choices. This could be done with 4 bits of information. Monitors today potentially display 256 colors, about 65,000 or 16.7 million colors. These are 8-bit, 16-bit and 24-bit, respectively. The computing power of the display card in the computer determines the number of colors. An 8-bit display only has 256 choices of color . It can pick any set of 256 colors from the possible 16.7 million colors that the monitor can create.

The 8-bit color display card must remember the 256 choices. It does this by putting the 256 color definitions into a Color Lookup Table (CLUT, also called the Color Palette). It must use those 256 colors to display everything on the screen at any moment. 16 and 24-bit displays have larger choices of colors. They can create nearly any color and don't rely on the Color Lookup Table. Graphic files can contain varying amounts of color data ranging from 1-bit to 24-bit. 32-bit files include a layer of masking information. Indexed Color - 8-bit meets 8-bit The Internet and multimedia frequently use 8-bit graphics and displays to keep file sizes small to accommodate the limited transmission speeds of the hardware they use. An 8-bit graphic has 256 possible colors, no more...but it can have less. The 8-bit graphic uses a CLUT, just as the monitor does. Every pixel in a graphic image is associated with a color on the CLUT. If a color on the CLUT is edited and redefined to be another color, the pixels in the graphic which used that position on the CLUT will change their displayed color to the newer color.

This relationship of graphic pixels to CLUT color positions is called INDEXING. An indexed color image has its own CLUT stored with it. If no other graphic has control of the CLUT contents, a new image can load its CLUT when it displays. If it can't, there may be some inappropriate colors. What does 24-bit do? 24-bit images contain three 8-bit channels of information; Red, Green and Blue. Every pixel is assigned three values, as shown in the bit mappped image example shown above. Since each color channel can have 256 variations, the total number of color combinations for every pixel is large, about 16.7 million colors. Most print grapics use 24-bit or 1-bit images. Some systems use more than 24-bit files but they aren't common. On the Internet, 24-bit graphics will display as best they can on the viewer's computer. If they are on a computer with a 16 or 24-bit monitor they will look great. If they are displayed on an older 8-bit monitor they can only use the 256 colors currently used by the system.

Some hardware and software can make adjustments on the fly to improve the display color selection. Some systems will not ...they use what ever Color Table (Palette, CLUT...same thing) is active. This may mean that if your computer can not find any blue colors in the palette to match a blue sky it will display the next closest match...a turquoise or purple, possibly. This has been a quick introduction to computer color display. Be sure to visit some of the web sites offering more detailed explanations of color. Adjusting Scale for Higher DPI Screens (Internet Explorer) Adjusting Scale for Higher DPI Screens Collapse the table of content Expand the table of content This documentation is archived and is not being maintained. This documentation is archived and is not being maintained. Adjusting Scale for Higher DPI Screens To improve the browsing experience for users with higher-resolution systems, Microsoft Internet Explorer 6 and later can automatically adjust the scale of the display. The following topics are discussed in this document. Related topics Pixels, Dots, and Resolution The terms pixel and dot are used interchangeably. Pixel is short for picture element (pix-el). It is a relative length unit that represents the smallest amount of information displayed on the screen as a single dot.

Screen resolution is expressed in dots per inch (dpi), which is the number of dots—or pixels—the screen displays per linear inch. The normal resolution on most systems is 96 dpi. Until recently, most computer hardware was not capable of producing higher resolution, but this is changing. Several hardware manufacturers, particularly manufacturers of laptop systems, are building systems capable of producing higher resolution. These systems will be available before the end of the year 2001. Images become crisper and text more legible as dpi increases. Because computer screens have sharper pixels and support gray scale, the text on a 200 dpi monitor is as clear as the printout from a 600 dpi laser printer. Note Screen resolution can also be expressed as the total number of pixels displayed horizontally and vertically—such as 640 by 480, 800 by 600, and 1024 by 768. For example, 640 by 480 means there are 640 pixels displayed horizontally and 480 pixels displayed vertically. Problems with Higher DPI A user interface that was designed to look good on a 96 dpi display may look unsightly at higher resolutions.

Text and graphics that are small at 96 dpi may appear much smaller at 200 dpi. When the number of pixels per inch increases, the size of the individual pixels decreases. Doubling the density of the pixels may halve the size of the text so that the text is no longer readable. Web pages that specify pixel sizes for containers and text appear half their size, and the layout around them is adjusted accordingly. Scaling is the Solution Internet Explorer 6 and later solves these problems by proportionally adjusting the scale on displays with higher resolution. When scaling is activated on a 192 dpi system, for example, an HTML element that has a specified height and width of 250 pixels has a scaled height and width of approximately 500 pixels. 192 DPI / 96 DPI * 250 pixels = 500 pixels ActiveX Controls and Binary Behaviors Scaling is not a perfect solution. Embedded Microsoft ActiveX controls, binary behaviors, and other elements that use Windows Windows Graphics Device Interface (GDI) calls scale poorly or not at all. The GDI does not perform automatic scaling based on the density of the display.

Web page authors should avoid using small graphics and images that don't scale well, such as images that contain sharp rendered text, or use different graphics when Windows Internet Explorer is adjusting the scale of the display. The following script uses the deviceXDPI and logicalXDPI properties of the screen object to calculate the horizontal scale factor that Internet Explorer is applying. The deviceXDPI property retrieves the actual dpi of the system's screen, and the logicalXDPI property retrieves the normal dpi of the system's screen. The function in this example returns 1 if Internet Explorer is not adjusting the scale of the screen. When deviceXDPI and logicalXDPI are equal, Internet Explorer is not adjusting the scale of the screen. Note You can use the deviceYDPI and logicalYDPI properties of the screen object to calculate the vertical scale factor that Internet Explorer is applying. On most systems, however, there is no difference between horizontal and vertical dpi.

<script> function fnScaleFactorX() { var nScaleFactor = screen.deviceXDPI / screen.logicalXDPI; return nScaleFactor; } </script> How to Activate Scaling Internet Explorer 6 and later automatically adjusts the scale on higher resolution systems when the dpi setting is higher than 96 dpi and the "UseHR" registry value is added to the registry. These are usually done by the manufacturers of higher resolution systems. Set the DPI These are the steps for changing the dpi setting on your system. Right-click the Windows desktop to display the context menu. Click Properties on the context menu to display the Display Properties dialog. Click the Settings tab on the Display Properties dialog to display the Settings tab. Click the Advanced button on the Settings tab to display the monitor properties dialog. Select a dpi setting in the Display frame of the monitor properties dialog to change the dpi setting. Restart your system to allow the changes to take effect.

Add the UseHR Registry Entry The UseHR value is added to the Main key under "Internet Explorer" as follows: HKEY_CURRENT_USER Software Microsoft Internet Explorer Main UseHR = dword:00000001 Related topics How to Fix Dead Pixel on Your Laptop Screen or LCD Monitor How to Fix Dead Pixel on Your Laptop Screen or LCD Monitor Posted by Nelda Yuntantri The most important thing you should do before buying a new laptop/LCD Monitor is to check whether there is a defective pixel in the LCD screen. There are two types of defective pixels, "dead pixels" and "stuck pixels". When a pixel never shows light, it's called dead pixel, but if that pixel always shows light (red, green, or blue) when your laptop is active, it's called stuck pixel. Yesterday I found a dead pixel on my Acer laptop.

I want to replace the laptop's LCD screen, but Acer Limited Warranty says : Minor defects of LCD displays occurring in Products equipped with LCD display technology, provided that there shall not be more than four (4) defective pixels per million pixels on a given LCD display, and provided further that, if the display panel is divided into nine (9) equal rectangular areas, there shall be one defective pixel in the central area of the display. Acer So it's not covered by the limited warranty and I decided try to fix it by myself. There are several methods to fix dead/stuck pixels, but first you should know where the location of the defective pixels. You can use Dead Pixel Buddy ( Download ) or UDPixel ( Download ) to find the defective pixels on your LCD screen.

Dead Pixel Buddy This method has been reported to work many times (for stuck pixels) Step 1: Open UDPixel > Flash windows: 1 > Flash size: 5x5 > Flash interval: 25ms > click Start If you found more than one defective pixel, change the Flash windows value to 2 Set Flash interval to 5ms if your LCD monitor has 5ms refresh rate Step 2: Drag the blinking dot, and then wait for a few hours. Alternative tools to do this method: Pressure Method First, locate the defective pixels and then you can use your finger to apply a gentle pressure/massage on the LCD screen, you don't need to turn off the monitor. Do not use your nail and make sure your nail is not sharp or it will accidentally scratch the screen surface. This method worked for me on my LCD monitor (dead pixels). Another pressure method: Turn off your computer's monitor. Get yourself a damp washcloth, so that you don't scratch your screen. Take a household pen, pencil, screwdriver , or some other sort of instrument with a focused, but relatively dull, point. A very good tool would be a PDA stylus.

(You can use your finger) Fold the washcloth to make sure you don't accidentally puncture it and scratch the screen. Apply pressure through the folded washcloth with the instrument to exactly where the stuck pixel is. Try not to put pressure anywhere else, as this may make more stuck pixels. While applying pressure, turn on your computer and screen. Remove pressure and the stuck pixel should be gone. This works as the liquid in the liquid crystal has not spread into each little pixel. This liquid is used with the backlight on your monitor, allowing different amounts of light through, which creates the different colors. For more information about this method, go to WikiHow Good luck ... Chapter 6 - Output Identify output options for physically challenged users In this chapter, you learn what is output and what are output devices. Display devices are introduced, including CRT monitors, flat-panel displays, video cards, and high-definition television. You explore monitor quality and monitor ergonomics. Various types of printers are presented, such as impact printers, nonimpact printers, portable printers, plotters and large-format printers, and special-purpose printers. You find out about audio output and other output devices, including data projectors, facsimile machines, and multifunction devices.

Finally, you become acquainted with terminals and output devices for physically challenged users. Define the four categories of output Output is data that has been processed into a useful form called information. Four types of output are text, graphics, audio, and video. Text consists of characters (letters, numbers, punctuation marks, or any other symbol requiring one byte of computer storage space) that are used to create words, sentences, and paragraphs. Graphics are digital representations of nontext information such as drawings, charts, photographs, and animation (a series of still images in rapid sequence that gives the illusion of motion). Audio is music, speech, or any other sound. Video consists of images played back at speeds to provide the appearance of full motion. An output device is any computer component capable of conveying information to a user. Identify the different types of display devices A display device is an output device that visually conveys text, graphics, and video information. Information shown on a display device is called soft copy because the information exists electronically and is displayed for a temporary period of time. Display devices include CRT monitors, LCD monitors and displays, gas plasma monitors, and televisions. A CRT monitor is a monitor that is similar to a standard television set because it contains a cathode ray tube.

A cathode ray tube (CRT) is a large, sealed, glass tube. The front of the tube is a screen coated with phosphor material that glows as an electron beam moves back and forth, which produces an image on the screen. LCD monitors and LCD displays use liquid crystal to present information on the screen. A liquid crystal display (LCD) has liquid crystals between two sheets of material. When an electric current passes through the crystals, they twist, causing some light waves to be blocked and allowing others to pass through, which creates the images. Similar to an LCD display, a gas plasma monitor is a flat-panel display. A gas plasma monitor, however, substitutes a layer of gas for the liquid crystal material. When voltage is applied, the gas releases ultraviolet light that causes pixels on the screen to glow and form an image. An NTSC converter converts a computerï¿½s digital signal into an analog signal that a standard television set can display. High-definition television (HDTV) is a type of television set that works with digital broadcasting signals and supports a wider screen and higher resolution than a standard television set.

Describe factors that affect the quality of a display device The quality of a CRT monitor depends largely on its resolution, dot pitch, and refresh rate. The quality of an LCD monitor or display depends primarily on its resolution. A CRT monitorï¿½s screen is coated with tiny dots of phosphor material, called pixels, that glow when electrically charged to produce an image. Resolution, which describes the sharpness and clearness of that image, is related directly to the number of pixels a monitor can display. The greater the number of pixels the display uses, the better the quality of the image. Dot pitch, a measure of image clarity, is the distance between each pixel on a display. The smaller the distance between pixels (dot pitch), the sharper the image. Refresh rate is the speed that a monitor redraws images on the screen. Refresh rate should be fast enough to maintain a constant, flicker-free image. The resolution of an LCD monitor or display generally is proportional to the size of the monitor or display. That is, the resolution increases for larger monitors and devices. Identify monitor ergonomic issues The goal of ergonomics is to incorporate comfort, efficiency, and safety into the design of items in the workplace.

Features that address monitor ergonomic issues include controls to adjust the brightness, contrast, positioning, and height and width of images. Newer monitors have digital controls that allow you to fine-tune the display. Many monitors also have a tilt and swivel base so the angle of the screen can be altered to minimize neck strain and glare. Monitors produce a small amount of electromagnetic radiation (EMR), which is a magnetic field that travels at the speed of light. High-quality monitors should comply with MPR II, a standard that defines acceptable levels of EMR for a monitor. Explain the differences among various types of printers A printer is an output device that produces text and graphics on a physical medium such as paper or transparency film. Printed information is called hard copy because the information exists physically and is a more permanent from of output. Printers can be grouped in two categories: impact and nonimpact. Impact printers form characters and graphics by striking a mechanism against an ink ribbon that physically contacts the paper. A dot-matrix printer is an impact printer that prints images when tiny wire pins on a print head mechanism strike an inked ribbon. A line printer is an impact printer that prints an entire line at one time.

Two popular types of line printers are band printers and shuttle-matrix printers. Nonimpact printers form characters and graphics without actually striking the paper. An ink-jet printer is a nonimpact printer that sprays drops of ink onto a piece of paper. A laser printer is a nonimpact printer that creates images using a laser beam and powdered ink, called toner. A thermal printer is a nonimpact printer that generates images by pushing electrically heated pins against heat-sensitive paper. Although the print quality of standard thermal printers generally is low, two special types of thermal printers, thermal wax-transfer printers and dye-sublimation printers, have a much higher print quality. Some printers are used for special purposes. A photo printer is a color printer that can produce photo lab quality pictures as well as printing everyday documents. A label printer is a small printer that prints on an adhesive type material that can be placed on a variety of items. A portable printer is a small, lightweight printer that allows a mobile user to print from a notebook or handheld computer while traveling. Plotters are sophisticated printers used to produce high-quality drawings such as blueprints, maps, and circuit diagrams.

A large-format printer, which operates like an ink-jet printer but on a larger scale, creates photo-realistic quality color prints. Describe the uses of speakers and headsets An audio output device produces music, speech, or other sounds. Two commonly used audio output devices are speakers and headsets. Most personal computers have an internal speaker that outputs low-quality sound. Many users add high-quality stereo speakers or purchase PCs with larger speakers built into the sides of the monitor. A woofer can be added to boost low bass sounds. A headset plugged into a port on the sound card allows only the user to hear sound from the computer. Identify the purpose of data projectors, fax machines, and multifunction devices A data projector takes the image on a computer screen and projects it onto a large screen so that an audience of people can see the image. Two smaller, lower priced data projectors are an LCD projector, which uses liquid crystal display technology, and a digital light processing (DLP) projector, which uses tiny mirrors. A facsimile (fax) machine transmits and receives documents over telephone lines. A fax modem is a communication device that allows you to send (and sometimes receive) electronic documents as faxes.

A multifunction device (MFD) is a single piece of equipment that looks like a copy machine but provides the functionality of a printer, scanner, copy machine, and sometimes a fax machine. Explain how a terminal is both an input and output device A terminal is a device that performs both input and output because it consists of a keyboard (input), a monitor (output), and a video card. A dumb terminal has no processing power and cannot function as an independent device. Dumb terminals connect to a host computer that performs the processing and then sends the output back to the dumb terminal. An intelligent terminal has memory and a processor that has the capability of performing some functions independent of the host computer. Some special-purpose terminals perform specific tasks and contain features designed for a particular industry. A point-of-sale (POS) terminal is a special-purpose terminal used to record purchases at the point where a consumer buys a product or service. An automatic teller machine (ATM) is a self-service, special-purpose terminal used to access your bank account. Identify output options for physically challenged users For users with mobility, hearing, or vision disabilities, many different types of output devices are available. For example, hearing-impaired users can instruct programs to display words instead of sound.

With the Windows operating system, physically challenged users can set options to make programs easier to use. Visually impaired users can change the size or color of text to make words easier to read. Blind users can use speech output, where the computer reads information that displays on the screen. A Braille printer outputs information in Braille onto paper. Output For computer users, output may be the most significant stage of the information processing cycle. Output is the goal of input and processing. It provides the information users need to work and make decisions. Output used by a machine often is an intermediate result. Eventually it will be processed into a form that can be used by people. Sound Blaster is the de facto standard for computer audio. You may be familiar with audio output from certain cars and vending machines: ï¿½Fasten seat beltsï¿½ or ï¿½Please deposit twenty-five cents.ï¿½ Voice output telephone calls promoting banks, services, or political candidates are increasingly common. Yet, audio output is not always welcome. Voice output once was employed in grocery store checkouts. Because of negative public reaction, however, it has been discontinued.

Display Devices Although ï¿½softï¿½ implies a touchable quality, soft copy only has an electronic, intangible existence, unlike the physical presence of hard copy (printed material). So much information today is in color that sales of monochrome monitors have plummeted. A number of less expensive monitors that use gray scaling, however, are popular among business users. The CRT in a monitor uses from 15,000 to 20,000 volts to accelerate electrons from the gun to the screen. Servicing of monitors, therefore, only should be done by trained personnel. Color monitors sometimes are known as RGB monitors (for red, green, and blue). Red, green, and blue are lightï¿½s primary colors. These three fundamental colors are not the same as the three primary pigments you may have mixed in art class (red, yellow, and blue). Believe it or not, when red light and green light mix the result is seen as yellow light. Application software sometimes requires a specific video standard for optimal performance. A factor to keep in mind when purchasing a monitor is that any video card capable of a higher resolution can run programs that require lower resolution levels ï¿½ a concept called backward compatibility.

The CGA standard monitor, introduced in 1981, had a 640 x 200 resolution and displayed four colors. Todayï¿½s SVGA monitor has a resolution more than 6 times better and can display 16.7 million colors. Although flat-panel displays use relatively little power and the clarity of the images they produce continues to improve, they are not as bright as CRT monitors. Because active matrix displays are much clearer than passive matrix displays, most of todayï¿½s notebook computers have active matrix displays. LCD screens often are backlighted but consume microwatts of power and give off virtually no heat. Gas plasma screens, while much brighter, consume hundreds or thousands of times more power than LCDs. Monitor Quality In some ways, pixel images on a monitor are similar to the works created by pointillist painters like Georges Seurat. The flickering that is seen on some monitors is a result of a too-slow refresh rate. Older monitors refresh images using a technique called interlacing, in which the an electron beam draws only half the horizontal lines with each pass. Most of todayï¿½s monitors are noninterlaced.

For the eyes, noninterlaced monitors tend to be less tiring than interlaced monitors. All video display devices look better in a dark environment. Varying requirements have led to the development of printers with different capabilities. In addition to the questions posed in Figure 6-15, the following factors should be considered when purchasing any printer: What is the total printer cost? (Supplies and maintenance should be weighed along with initial price.) How much is the printer used? (The duty cycle, or recommended maximum output per month, and the mean time between failure (MTBF), or estimated time before a component needs service, are key considerations.) What type of output will be produced? (A printerï¿½s capabilities must match output requirements.) Who will use the output? (External correspondence requires better quality printing than internal-only reports.) Are multiple copies necessary? (Only impact printers can produce multiple copies on a single pass.) Is color required? (Color significantly adds to the cost of some printers.) Where will the printer be used? (Impact printers are noisy in closed locations, but are more resistant to extreme conditions.) For a printer to function, the appropriate printer driver must be installed in the computer.

Drivers are software that transform the computerï¿½s output into signals a printer can understand and use. Most printer manufacturers include driver software. Because most printers are 1,000 times slower than computers, all printers have a buffer that temporarily stores a few pages, allowing the computer to dump output into the buffer and continue processing. Print quality depends on dots per inch and the amount of overlap. Letter quality (LQ) print corresponds to that produced by a typewriter. Many impact printers produce near letter quality (NLQ) print, which is slightly less clear than letter quality. Although most dot-matrix printers use continuous-form paper (in which individual sheets are connected together), some also can use single-sheet paper without removing any paper by ï¿½parkingï¿½ continuous-form paper while a single sheet is printed. Nonimpact printers represent the fastest growing segment of the printer market. One attraction of nonimpact printers is their quiet operation. Imagine the noise level in an office with several impact printers operating simultaneously! Due to separate development, printer resolution is expressed in dots per inch while monitor resolution is stated in pixels per inch (which is dependent on dot pitch).

The resolution of a high-end printer is about 10 times better than the resolution of an SVGA monitor. Although high resolution is good, more dpi requires additional memory. Unlike other types of nonimpact printers, the image produced by ink-jet printers can smear if moistened. Although laser printers are popular, they do not handle all printing jobs well. Special feeders are needed to print multiple envelopes, and multipart forms cannot be used at all. Audio Output Like other computer components, high-quality speakers are growing smaller. NXT has developed speakers for its flat-panel technology that deliver superior sound despite being only one sixty-fourth of an inch thick. The speaker technology has been licensed by NEC, Acer, and Mission and is included in their new PCs and notebooks. Other Output Devices Data projectors are particularly useful when demonstrating computer software packages. A data projector, along with the modem-equipped notebook computer and portable printer, is part of the arsenal of business travelers. With these weapons, the ï¿½road warriorï¿½ can create, transmit, receive, and project sales presentations. Which device ï¿½ a stand-alone fax machine or a fax modem ï¿½ would be most useful for a home user. For a small office?

For a large office? Why? Under what circumstances might you consider purchasing an MFD. Why? Terminals Terminals also sometimes are called display terminals or video display terminals (VDTs). Historically, terminals have been dumb and dependent on a mainframe, to which they were connected by a cable, called an umbilical cord, for any processing. The advent of inexpensive personal computers gave rise to terminals with independent processing capabilities. Personal computers that function as intelligent terminals are connected to switch boxes that allow them to operate as PCs or to access a mainframe. Although they are intelligent terminals, some workstations are designed without disk drives so restricted data cannot be downloaded or copied. Some terminals, such as credit card authorization devices in department stores, look very little like normal computers. POS (point-of-sale) terminal printers are special-purpose printers used at supermarket checkouts. These usually are low-grade dot-matrix printers that have seven or nine pins. Output Devices for Physically Challenged Users If, when using Windows, the Accessibility command does not appear on the Accessories submenu, you may have to install Accessibility Options.

To install Accessibility Options, open the Add/Remove Programs Properties dialog box at the Windows Setup tab by clicking Start, pointing to Settings, clicking Control Panel, double-clicking Add/Remove Programs, and then clicking the Windows Setup tab. If you used a CD to install Windows, you will be prompted to insert it into your computer. Under Components, click to select the Accessibility Options check box and then click OK. In Windows, the Accessibility Properties dialog box can be used to change both input and output options for physically challenged users. To open the Accessibility Properties dialog box, click the Start button, point to Settings, click Control Panel on the Settings submenu, and then double-click the Accessibility Options icon in the Control Panel dialog box.

The Accessibility Properties dialog box can be used to change: Keyboard options ï¿½ StickyKeys (allows the shift, >alt, and ctrl keys, which usually are used with other keys, to be used by pressing one key at a time), FilterKeys (ignores brief or repeated keystrokes), and ToggleKeys (plays a tone when a toggle key is pressed) Sound options ï¿½ SoundSentry (generates visual warnings when a sound is made) and ShowSounds (displays captions for program speech and sound) Display options ï¿½ High Contrast (uses colors and fonts designed for easy reading) Mouse options ï¿½ MouseKeys (allows pointer to be controlled with the numeric keypad)

Question: What is the name of a single dot on a computer monitor screen?
Answer: Pixel